Elastic yarn and fabric



March 2,1937. H A, SMITH HAL 2,072,775

ELASTIC YARN AND FABRIC Filed Feb. 25. 1936 4 We I m 4/ 5 I l l M #45010 Af i l ATTORNEY.

Patented Mar. 2,2193? UNITED STATES PATENT OFFICE ELASTIC YARN AND FABRIC Harold A. Smith, Needham, Mass., and Joseph J. Fodor, Yonkers, N. Y., assignors to Frank W.

Gorse Company, Needham Heights, Mass., a

12 Claims.

This invention relates to improvements in elastic yarn having a limited stretch and to a fabric employing this elastic yarn in its construc tion.

. Elastic yarns consisting of a rubber core having one or more covers wound helically about the core are extensively used in knitted; woven and other fabrics to impart elastic properties to these fabrics, but since such yarns are usually capable of stretching from one to several times their length from the relaxed condition, difiiculty is experienced in introducing these elastic yarns in fabrics under the desired tension..

. Furthermore, when elastic yarn is introduced 5 in the fabric so that it is maintained under tension inv the finished fabric, as is the general practice in woven, elastic fabrics, 'difliculty is experienced if the fabric is cut transversely of the elastic yarn, due to the tendency of the tensioned elastic-yarn to run or pull back in the fabric.

Likewise, difliculty is experienced in sewing elastic fabric because if the sewing needle cuts the elastic yarn it will tend to run or pull back in the fabric. When an elastic yarn is cut and pulls back in the fabric it not only forms a defective place in the fabric or garment in which it is embodied but the loose rubber end is likely to protrude from, the face of the fabric and form what is called a black-head.

The present invention seeks to overcome these diificulties and one feature of the present invention resides in an elastic yarn having a stay or stop thread extending longitudinally of the elastic yarn and confined between its inner and outer helically wound covers. This stay thread serves to limit the stretch of the yarn as it is being introduced into thefabric and also to limit the stretch of the yarn in the finished fabric. An

elastic yarn having a limited stretch is easier to weave or knit and the stay thread prevents the yarn from stretching suificiently in the fabric to break the core or cover wound thereupon.

Another feature of the present invention resides in the construction whereby the stay thread above mentioned is arranged to form loops that bulge outwardly between helical coils of the outer cover when the elastic yarn is not fully extended. The effect of this is to give the elastic yarn a rough outer surface which causes it to be more firmly held inthe fabric, thus decreasing the tendency of the elastic yarn to slip inthe fabric. The stay thread further tends to hold the end of the core in the fabric when it is cut so that the rubber end will not protrude from the fabric to form an objectional black-head.

A further and important feature resides in the construction whereby the projecting loop formed along the elastic yarn are utilized to positively lock the elastic yarn in place in a knitted fabric. This is accomplished by so forming these loops 5 that some of the knitted loops may pass through the loops along the elastic yarns to lock the elastic yarns in place.

The above and other features of the invention will be more fully understood from the following 10 description when read in connection with the accompanying drawing illustrating one good practical form of the invention.

In the drawing:

Fig, 1 is a side view of a piece of elastic yam 15 constructed in accordance with the present invention, the yarn being shownas fully extended;

Fig. 2 is a similar view showing the yarn relaxed.

Fig. 3 on a larger scale is a section on line 3-3 20 of Fig. 1;

Fig. 4 is a similar section taken on the line Fig. 5 is a face view of a piece of knitted fabric having the elastic yarn of Fig. 2 locked to the 5 fabric in accordance with the present invention;

and Fig. 6 is a side elevation of a core covering machine which may be employed in manufacturing the yarn of the present invention.

The elastic yarn Y of the present invention has an elastic core ll] formed of rubber or rubberlike material. This core may be round or square or of any other desired shape in cross-section and may be made in any well known or pre- 35 ferred manner. The core illustrated is round in cross-section and may be formed by extrud-r ing or streaming latex into a coagulant. v

The core I0 is shown as provided with an inner cover II and outer cover It and the cover It in 40 the construction shown is formed of a textile thread wound helically about the core in one direction while the outer cover is formed of a group of textile threads l2 wound helically about the core inthe opposite direction. The group 45 I2 shown comprises three threads disposed side by side.

In accordance withthe present invention a stay or stop thread I3 is provided longitudinally of the core l0 between the inner and outercovers 50 as shown. In constructing the present elastic yarn the inner cover H is wound about thecore It! in spaced helical coils while the core is stretched to a substantial degree, and while this tension is maintained upon the core the stay 56 thread I3 is laid along the core against the open helical coils of the cover II, and the second cover I2 is then wound in the opposite direction in open helical coils about the cover H and stay 5 thread l3 as will be apparent from Fig. l. The construction is such that when the tension upon the elastic yarn of Fig. 1 is relaxed the core will contract until the helical windings of the inner and outer covers are moved into contacting rela- 10 tion to each other as s own in Fig. 2, and these covers when in this position preferably maintain I the core l under some tension. Since the stay thread I3 is securedto the elastic yarn while the latter is in the stretched l condition of Fig. 1, it is apparent that as the elastic yarn is permitted to contract the stay thread l3 will become relaxed and as a result the relaxed or slacked portions of the thread will bulge outwardly between the spaced helical wind- 20 ings of the group of outer threads 12 to form the loops l3:c, as will be apparent from Figs. 2

and 4. These loops I31: will disappear each time the. elastic yarn is stretched fully as shown in Fig. 1 and will reappear each time the elastic 5 yarn is permitted to contract, and as a result the elastic yarn Y due to these laterally projectin loops 131: will have a relatively rough outer surface, except when the yarn is fully extended, which rough surface will cause the elastic yarn it may be embodied.

- The present invention. contemplates that the laterally projecting loops I31: may be employed to lock the elastic yarn Y in place in a knitted fabric 35 when such'yarn is employed as a laid-in elastic yarn extending in The manner in which these loops may be employed to lock the elastic yarn in place in a knitted fabric is clearly shown in Fig. 5 wherein '40 an ordinary rib knitted construction is shown as formed of the knitted yarn l4, and it will be noted that" some of the loops formed of the knitted yarn M are passed through the anchoringloops I31: of the elastic yarn Y. The effect 45 of this is to firmly lock the laid-in elastic yarn in place in ,the I itted construction so that it is prevented from slipping or pulling back there:

in when the core I0 is cut.

It should be noted that by forming the outer 50 cover of several yarns l2 laid side by side and wound helically about the. core the stay thread l3v when relaxed will project outwardly along one sid of the-core between the'adjacent turns of the helically wound group-of threads so that the- 55 loops I32: will be spaced at regular intervals along I one side of the elastic yarn Y as shown. This spacing of the loops 131: "preferably bears a definite relation to adjacent wales of the 0 as the fabric the knitting needles passing through some of the anchoring loops 131: will be increased, with the result that during the knitting operation at least some of the knitting loops will be passed through the anchoring loops I31: as shown in Fig. 5

to firmly anchor the elastic yarn Y in place in the knitted fabric. The loops I32: may be pressed or sized or otherwise treated to hold them open so as to facilitate 70 needle therethrough. The elastic yamY'may also be used in hand knitted work, in which case the knitting loops ll may be directed by hand through the loops I33. Y I

when the elastic yarn of the present invention 75 is employed in woven or other fabrics in which knitted fabric 14 so that the elastic yarn that it to be more firmly held in the fabric in which the direction of the courses.

the distance between the I4 is being knitted the chance of I the passage of the knitting sip-12,775

the anchoring action disclosed in Fig. 5 cannot be obtained, the rough outer surface imparted to the elastic yarn by the projecting loops l3a: will enable this yarn to be more finished fabric and will lessen the tendency of the elastic yarn when the core "I0 is severed. Furthermore, if the core should be broken or cut, for example, by the needle employed in sewing the fabric, the stay thread l3 extending lengthwise of such core will tend to hold the core in place and lessen the likelihood of a cut rubber end projecting outwardly from a face of the fabric to form what is known as a blackhead.

The stay thread I3 is preferably so secured in and the covering yarns II and I2 from being extended to the breakingpoint. When this yarn Y is woven, knitted or otherwise introduced into a fabric,'it may be placed therein under uniform tension, by simplyexerting sumcient tension on the yarn during the weaving or knitting operation to hold the stay thread of the yarn taut. When, however, it is desired to produce the looking construction of Fig. 5 in which some of the knitted loops l4 pass through the anchoring loops 13:22, the elastic yarn Y should'be at this time only firmly held in the.

to' run or pull back in the fabric will prevent the core I0.

slightly extended sees not to cause the loops I3a: to disappear.

Various formsof mechanism may be employed in constructing the elastic yarn forming the subject matter of the present invention and one form of mechanism to this end'is shown more or less diagrammatically in Fig. 6, wherein the. elastic core I0 is shown as passing upwardly through a hollow lower spindle l5 and a hollow upper spindle IS. The core is drawn upwardly through these spindles under tension by means to be described and the spindles are rotatably'supported in vertical alignment with each other. Upon the lower spindle I5 is mounted a yarnsupply spool II; The spindle I5 is driven by a whirl 18 and belt l9 and surrounding the supply spool I1 is a ring 20 and traveler 2| of usual construction. The arrangement is such that as the yarn l l for the inner cover of the core is unwound from the supply spool I I spool may have the three threads I! wound therei upon in side by side relation and as these threads are unwound from the spool they pass through the traveler 26 supported by the ring 21. The spindle I6 and spool 25 are rotated in the opposite direction by a driving belt 28 from that of the spool II. The efiectof this is to wrap the three threads l2 side by side in open helical coils about the covered core l0 and stay thread l3 in an'opposite direction to the thread ll of the inner cover.

The core-Hi may be supplied to the winding mechanism of Fig. 6 from a spool, not shown, but the rotation of which is retarded to tension the core as it passed upwardly through the spindles l5 and IS. The finished elastic yarn Y may be drawn upwardly by a constantly rotating drum 29 having the yarn held thereagainst by a roller the inner cover ll wound thereupon passes 'up- 15 contact with thecore It). In

20 Patent is:

5. l2 that this thread when relaxed is permitted to project outwardly between the helical coils of the cover, the stay thread serves not only to limit the stretch of the elastic yarn Y but also to provide a rough surface upon the yarn which 10 enables it to be more firmly held in the fabric as above pointed out. Some of the advantages of the present invention may be obtained if the inner cover II is omitted in which case the outer cover l2 will secure the stay thread I3 in direct this case the loops I31: will be produced when the yarn Y is relaxed as in the construction illustrated.

Having thus described our invention what we claim and desire to have protected by Letters 1. An elastic yarn'comprising an elastic core, inner and outer covers wound helically about the core, a thread extending lengthwise of the core between the inner and outer covers and arranged to form loops projecting outwardly between the V helical windings of the outer cover when the elastic yarn is in the relaxed condition.

2. An elastic yarn comprising an elastic core,

inner and outer covers wound helically about 30 the core, a stay thread extending along the core between the inner and outer coversto limit the stretch of the elastic yarn and arranged to project outwardly between the windings of the outer cover when the elastic yarn is' in the relaxed coli- 35 dition. V

3. An elastic yarn comprising an elastic core,

a cover wound helicallyaboutthe core, and yarn loops extending laterally outwardly from the elastic yarn and anchored thereto by the hellcally wound cover.

' 4. An elastic yarn comprising an elastic core, a cover wound helically about the core, and a row of yarn loops extending outwardly from one side of the elastic yarn and anchored thereto by the helically wound cover.

5. A yarncomprising a core, acover wound helically about the core. and strand loops extending outwardly from the yarn and anchored thereto by the helically wound cover.

6. A yarn comprising a core, a cover of fibrous strand wound helically about the core, and strand loops extending outwardly from the yarn and anchored thereto by the helically wound cover.

7. An elastic yarn comprising an elastic core.

an inner cover wound helically about the core in one direction and an outer cover wound helically about the core in the opposite direction, and a. series of yarn loops extending laterally outward from the elastic yarn and secured thereto by the outer cover.

8. An elastic yarn comprising an elastic core, a cover wound helically about the core, and loops formed of a yarn much smaller in diameter than the elastic yarn and anchored thereto by said cover to project outwardly beyond the cover.

9. An elastic yarn comprising an elastic core, a cover upon the core formed of a helically disposed group of fibrous threads and a thread extending lengthwise of the core and forming loops projecting laterally outwardly from the core between the adiacent turns of said helical group of threads.

10. A knitted fabric embodying therein a plurality of elastic strands each formed with anchoring loops extending laterally therefrom, said strands being placed in the fabric in parallel relation to each other and having loops of the knitted fabric extending through the strand loops, whereby the elastic strands are locked in the fabric.

11. A knitted fabric embodying therein a plurality of elastic strands each comprising a core, a helically wrapped cover upon the core and anchoring'loops secured to the core by the cover, said strands being placed across the fabric and having loops of the knitted fabric extending through said anchoring loops to lock the strands to the fabric.

12. An elastic fabric embodying therein a plurality of elastic strands each formed with a series of loops extending laterally therefrom to form upon the strands a rough outer surface, and

other strands engaging said rough elastic strands and firmly holding them in the fabric.

HAROLD A. SMITH. JOSEPH J. FODOR. 

